Multi-energy spectrum X-ray grating-based imaging system and imaging method

A multi-spectrum X-ray grating-based imaging system, comprising:

• an incoherent X-ray source, for emitting X-rays to irradiate an object to be detected;
• a grating module, comprising a first absorption grating and a second absorption grating which are disposed in parallel to each other and are sequentially arranged in an X-ray propagation direction;
• an energy-resolved detecting device, for receiving the X-rays that have passed through the first absorption grating and the second absorption grating, and
• a source grating, disposed at a position between the incoherent X-ray source and the object to be detected and adjacent to the incoherent X-ray source, wherein the source grating is configured to move in a direction parallel to the first absorption grating and the second absorption grating,
• wherein the grating module is configured such that the first absorption grating and the second absorption grating are fixed, while the source grating is configured to perform phase stepping actions in at least one period,
• wherein during each phase stepping action, the incoherent X-ray source emits X-rays to irradiate the object to be detected, and the energy-resolved detecting device receives the X-rays and performs spectrum identification of the received X-rays, and
• wherein after a series of phase stepping actions and data acquisitions over a period, at each pixel on the energy-resolved detecting device, X-ray intensities in each energy range are represented as an intensity curve.

An X-ray grating-based imaging method, comprising:

• enabling one of a first absorption grating and a second absorption grating which are parallel to each other and are sequentially arranged in an X-ray propagation direction to perform phase stepping actions within at least one period, wherein during each phase stepping action, an incoherent X-ray source emits X-rays to irradiate an object to be detected, and an energy-resolved detecting device receives the X-rays that have passed through the first absorption grating and the second absorption grating and performs spectrum identification of the received X-rays;
• after a series of phase stepping actions and data acquisitions over a period, representing X-ray intensities in each energy range, at each pixel on the energy-resolved detecting device, as an intensity curve;
• calculating pixel values at each pixel by comparing an intensity curve at each pixel on the energy-resolved detecting device to an intensity curve in the absence of the object to be detected;
• and
• obtaining image information of the object to be detected according to the pixel values.